1. Field of the Invention
The present invention relates to a liquid crystal display, particularly to a liquid crystal display that displays a 2D/3D region through enabling a plurality of second enable lines coupled to a second driving circuit and a plurality of first enable lines coupled to a first driving circuit in groups.
2. Description of the Prior Art
Please refer to FIG. 1, which is a diagram of a liquid crystal display 100 capable of displaying a 2D/3D region. As shown in FIG. 1, liquid crystal display 100 comprises display panel 102, switch cell (SW) 104 and lenticular lens layer 106. When liquid crystal display 100 displays a 3D region, it acts as an automatic 3D display, and liquid crystal display 100 displays a 2D region or 3D region by controlling liquid crystal molecule twisting angle in switch cell 104 and using lenticular lens layer 106.
Please refer to FIG. 2A, FIG. 2B, and FIG. 2C. FIG. 2A is a diagram illustrating a driving method of switch cell 104. FIG. 2B is a diagram illustrating first voltage VON corresponding to region A and second voltage VOFF corresponding to region B of FIG. 2A, where region A is used for displaying a 3D region, and region B is used for displaying a 2D region. FIG. 2C is a diagram illustrating relationship between voltage selection ratio (VON/VOFF) and switch cell 104 resolution. As shown in FIG. 2A, second enable lines S1-SN of switch cell 104 are enabled sequentially, where t1-tN are times corresponding to second enable lines S1-SN, and N is a positive integer. When second enable lines S2 (time t2), S3 (time t3) corresponding to region A and region B are enabled, first enable lines of first enable lines D1-DM corresponding to region A receive a low voltage −VSEL, and first enable lines of first enable lines D1-DM corresponding to region B receive a high voltage VSEL, where M is a positive integer. Further, as shown in FIG. 2A, because second enable lines S1, S4-SN do not correspond to region A, when second enable lines S1, S4-SN are enabled, first enable lines D1-DM all receive high voltage VSEL. As shown in FIG. 2B, first voltage VON corresponding to region A is voltage difference between low voltage −VSEL and voltage VS enabling second enable lines S1-SN, and second voltage VOFF corresponding to region B is voltage difference between high voltage VSEL and voltage VS enabling second enable lines S1-SN (the above signals invert polarity during polarity inversion). As shown in FIG. 2C, with increased switch cell 104 resolution (higher number N of second enable lines), voltage selection ratio approaches closer to 1. In other words, difference between root mean square of first voltage VON and root mean square of second voltage VOFF decreases. Thus, because difference between liquid crystal twisting angles of region A and region B of switch cell 104 is not large, boundary between region A and region B exhibits cross talk. Particularly, when switch cell 104 is a twisted nematic liquid crystal, crosstalk becomes especially noticeable, because voltage selection ratio to resolution curve has gentle slope, and voltage selection ratio approaches 1 when resolution is high.